How long does custom injection molding take?

It depends. Prototype tooling can provide T1 samples as fast as 10 days. Production molds require additional time for machining, trials, correction, and validation.

Do you provide DFM analysis before tooling?

Yes. We review draft angles, wall thickness, ribs, bosses, gates, shrinkage, and tooling risks before mold development.

What is the difference between insert molding and overmolding?

Insert molding integrates components such as metal inserts into plastic parts. Overmolding combines multiple materials, such as rigid plastic and soft elastomers, into one part.

What materials are available for custom injection molding?

Mastars supports a wide range of injection molding materials, including standard plastics, engineering plastics, high-performance polymers, and elastomers. Common materials include ABS, PC, PP, PA (Nylon), POM, PEEK, PPS, TPE, TPU, and silicone rubber. Material selection depends on mechanical requirements, temperature resistance, chemical exposure, appearance, and end-use application.

What industries do your plastic injection molding services support?

Our injection molding solutions support a wide range of industries, including automotive, medical devices, consumer electronics, electrical components, home appliances, industrial equipment, and personal care products. We help customers develop plastic parts from early prototypes to production volumes with engineering support, tooling management, and quality control.

Can you make injection molded prototypes before production?

Yes. Prototype injection molding validates fit, function, appearance, and material behavior before production tooling investment.

What CAD files should I send?

STEP/STP or IGES files are preferred. Add drawings when GD&T, critical dimensions, or surface requirements must be controlled.

No fixed MOQ. We support prototypes, bridge production, and production molding based on project requirements.

How much does custom injection molding cost?

It depends on mold type, part complexity, material, cavity count, finish, quantity, and inspection requirements.

When should I choose injection molding instead of 3D printing or CNC machining?

Choose injection molding when you need production-grade material behavior, repeatability, and lower unit cost at increasing volumes.

Injection Molding

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Services

Injection Molding

10^Days

T1 Samples

0.002^mm

Mold Precision

50^–60

Tools / Month

1^–100K

Units Supported

Injection Molding Capabilities

Plastic Injection Molding

Single-material thermoplastic parts from prototype tooling to repeat production. Suitable for functional validation, low-volume builds, and scalable manufacturing.

Silicone Rubber Molding

LSR molding for seals, gaskets, wearable parts, and other flexible components. Venting, flash, parting lines, cure behavior, and material-grade requirements are defined before tool release.

Insert Molding

Mold plastic or silicone around metal inserts, threaded hardware, or functional components to reduce assembly steps and create stronger interfaces. Insert location, retention, and thermal expansion must be controlled.

Over Molding

Combine rigid substrates with compatible TPE, TPU, silicone, or other materials for grip, sealing, impact protection, and integrated soft-touch features. Bonding and differential shrinkage are reviewed before tooling.

Family & Multi-Cavity Molding

Use multiple cavities to increase output or family tooling to mold related parts in one tool. Best when demand is stable enough to justify greater tooling complexity; cavity balance and cooling must be validated.

Plastic Tooling

Explore mold development for plastic component projects, from design review to tooling preparation. Tooling material, layout, and production requirements need project review.

Which Injection Molding Process Is Right for Your Part?

Compare process options based on material, part function, tooling strategy, and production volume.

Process	Best For	Material Options	Key Advantages	Typical Applications	Engineering Considerations
Plastic Injection Molding	Single-material thermoplastic parts where molded material behavior, repeatability, and unit cost matter	ABS, PC, PC+ABS, PP, PE, PA, POM, PBT/PET, PEEK, PPS, TPE/TPU	Broad resin choice, repeatable geometry, lower unit cost as volume grows	Housings, brackets, clips, gears, structural and functional parts	Draft, wall thickness, ribs, bosses, gates, shrinkage, warpage, ejection and cosmetic faces
Overmolding	Rigid-soft or multi-material parts requiring grip, sealing, protection or integrated functions	ABS, PC, PA or PP substrates with compatible TPE, TPU or silicone	Combines functions and can remove adhesives, fasteners or secondary assembly	Handles, grips, seals, housings, wearable products	Bond compatibility, mechanical interlocks, differential shrinkage, shutoffs and substrate distortion
Insert Molding	Parts with molded-in threads, electrical contacts or load-bearing inserts	Thermoplastics or LSR with brass, steel, stainless steel or aluminum inserts	Integrates hardware into one molding step and reduces later assembly	Connectors, threaded parts, sensors and mechanical assemblies	Insert tolerance, retention, positioning, thermal expansion and molding pressure
Liquid Silicone Rubber Molding	Flexible parts requiring elasticity, temperature stability or grade-specific medical use	Standard, medical-grade, transparent and colored LSR	Stable elasticity, fine-detail molding and automated repeat production	Seals, gaskets, wearable parts and flexible medical components	Venting, flash, parting lines, shrinkage, cure/post-cure and cleanliness requirements
Family & Multi-Cavity Molding	Stable medium- or high-volume demand, or related parts produced together	Most injection-molding thermoplastics	More parts per cycle and lower part cost when volume justifies the tooling	Repeat consumer, automotive and industrial programs	Cavity balance, cooling, runner/gate design, tool investment and cavity-to-cavity variation
Prototype / Bridge Tooling	Design validation, low-volume production, and market testing before production tooling	Aluminum or soft steel tooling with production-grade resins	Faster iteration and lower upfront investment before committing to production molds	Functional prototypes, pilot builds, short-run parts	Tool life, dimensional validation, and when to transition to production tooling

From Injection Molding Prototypes to Production Parts

Injection Molding Prototyping

Validate fit, assembly, function, appearance, and material behavior before investing in production tooling.

T1 samples as fast as 10 days
Production-grade resin validation
Fit, sealing & assembly checks
Flash, warpage & cosmetic review

Explore Injection Molding Prototyping

Injection Molding Production

Scale approved designs with repeatable tooling, stable processes, and production inspection.

1 to 100,000 units supported
Steel tooling for repeat production
Process consistency across production runs
FAI, CMM & critical-dimension control

Explore Injection Molding Production

Custom Injection Molding Services for Complex Projects

Mastars supports complex injection molded parts involving deep undercuts, inserts, thin walls, sealing surfaces, cosmetic faces, and tolerance-critical features. Sliders, lifters, side actions, 2K or overmolding, and post-machined interfaces can be planned as one manufacturing route instead of becoming separate supplier problems.

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Injection Molding Tolerances & Dimensional Control

Mold accuracy does not equal molded-part tolerance. Final dimensions depend on resin behavior, geometry, cooling, and process control.

Process / Capability	Typical Tolerance	Key Factors Affecting Accuracy	Typical Applications
Standard Plastic Injection Molding	Typically ±0.1–0.3 mm, depending on part size, geometry and resin	Material shrinkage, wall thickness, cooling, mold accuracy and process stability	Housings, consumer parts and general industrial components
Precision Injection Molding	Selected critical features down to ±0.05 mm depending on part geometry, tooling, and process control.	Mold accuracy, resin behavior, datum scheme, cooling, process window and inspection method	Precision assemblies, medical and automotive components
Overmolding	Project-specific; tolerance stack depends on substrate and overmold	Substrate tolerance, shutoff geometry, bonding interface, differential shrinkage and distortion	Soft-touch parts, seals and protective features
Insert Molding	Project-specific relative to insert datum and positioning	Insert tolerance, fixture location, thermal expansion, retention and molding pressure	Threaded components, connectors and integrated assemblies
LSR Molding	Typically ±0.1–0.3 mm on suitable features	Material shrinkage, venting, flash, cure/post-cure and parting-line design	Seals, gaskets and flexible components
Multi-Cavity / Family Molding	Follows the base molding process; cavity-to-cavity variation must also be qualified	Filling balance, cooling balance, gate/runner design and cavity variation	Medium- and high-volume repeat production

Injection Molding Materials

Material selection affects strength, shrinkage, appearance, and long-term performance.

ABS / PC+ABS

Polypropylene (PP)

Polyethylene (HDPE / LDPE)

Polycarbonate (PC)

Nylon

Polyoxymethylene

PEEK

PPS

Liquid Silicone Rubber (LSR)

TPE / TPU

ABS / PC+ABS

ABS is a cost-effective choice for housings and general structural parts with balanced impact resistance and cosmetic performance. PC+ABS blends add heat and impact capability while retaining good moldability and finishing options.

Key Characteristics

Balanced impact and stiffness

Good cosmetic surfaces

Easy to paint or plate

PC+ABS options for higher heat and impact requirements.

Typical Applications: Electronics housings, automotive interiors, appliance parts, industrial enclosures.

Available Finishes: Shrinkage, gloss, and plating performance vary by grade. Gate and flow planning matter on visible surfaces.

Polypropylene (PP)

PP combines low density, chemical resistance, and good fatigue performance, making it especially useful for lightweight parts, living hinges, containers, and chemical-contact applications.

Key Characteristics

Lightweight

Excellent chemical resistance

Good hinge fatigue

Low moisture absorption

Typical Applications: Caps, containers, living hinges, automotive parts, laboratory products.

Available Finishes: Relatively high shrinkage can increase warpage risk. Low surface energy means painting and bonding often require surface treatment or primer.

Polyethylene (HDPE / LDPE)

PE provides toughness, chemical resistance, and very low moisture absorption. Grades range from flexible LDPE to stiffer HDPE and are often selected for containers, protective parts, and fluid-handling applications rather than precision mechanisms.

Key Characteristics

Chemical resistance

Impact toughness

Low moisture absorption

Low-friction surface.

Typical Applications: Packaging, containers, fluid-handling parts and protective components.

Available Finishes: Low surface energy makes adhesion difficult, and comparatively high shrinkage must be considered where dimensional control matters.

Polycarbonate (PC)

PC is selected when high impact strength, heat resistance, or transparency is important. Optical appearance depends on resin grade, mold polish, gate flow, and control of molding stress.

Key Characteristics

High impact strength

Transparent grades available

Good heat resistance

Good dimensional stability

Typical Applications: Protective housings, transparent covers, lighting components and medical-device housings.

Available Finishes: Residual stress can contribute to crazing or chemical cracking. Clear cosmetic parts require careful polishing, gating, drying, and process control.

Nylon

Nylon offers strong mechanical, wear, and fatigue performance. Glass-filled grades increase stiffness and heat resistance, but fiber orientation can create directional shrinkage and warpage.

Key Characteristics

High mechanical strength

Good wear resistance

Strong fatigue performance

Reinforced grades available

Typical Applications: Gears, clips, brackets, automotive parts and structural components.

Available Finishes: Nylon absorbs moisture, which can change dimensions and mechanical behavior after molding. Drying and conditioning requirements should be defined early.

Polyoxymethylene

POM is a strong choice for precision mechanical parts requiring low friction, wear resistance, and stable sliding behavior.

Key Characteristics

Low friction

Good wear resistance

High stiffness

Good dimensional repeatability for mechanical components.

Typical Applications: Gears, bearings, sliding components and precision mechanisms.

Available Finishes: POM is crystalline and has meaningful molding shrinkage. Its low surface energy also makes painting and adhesive bonding difficult.

PEEK

PEEK is used when high temperature, chemical resistance, and mechanical performance justify a high-performance resin and a more demanding molding process.

Key Characteristics

High temperature capability

Chemical resistance

Mechanical strength

Long-term stability

Typical Applications: Aerospace, semiconductor, industrial and demanding medical-device components.

Available Finishes: Resin cost and molding temperatures are significantly higher than standard engineering plastics. Medical or regulated grades must be specified according to actual compliance and traceability requirements.

PPS

PPS provides strong thermal and chemical stability with low moisture absorption and is commonly supplied in glass- or mineral-filled grades.

Key Characteristics

Heat resistance

Chemical resistance

Low moisture absorption

Good dimensional stability

Typical Applications: Automotive components, electrical connectors, semiconductor and industrial equipment parts.

Available Finishes: Filled grades improve stiffness but increase tool wear and can create fiber-orientation effects. Mold temperature and flow must be considered for thin or complex sections.

Liquid Silicone Rubber (LSR)

LSR is selected for flexible components that require elasticity, temperature stability, sealing performance, or grade-specific medical use.

Key Characteristics

Flexible and elastic

Broad service-temperature capability

Weather and chemical resistance

Medical-grade options available.

Typical Applications: Seals, gaskets, wearable components and flexible medical parts.

Available Finishes: Shore hardness, compression set, flash, parting lines, venting, and post-cure requirements should be defined according to the actual function.

TPE / TPU

TPE and TPU provide flexible surfaces for grip, impact protection, sealing, and overmolding. TPU generally offers stronger abrasion and tear resistance, while TPE covers a wider range of soft-touch formulations.

Key Characteristics

Flexible

Soft-touch options

Impact protection

Multiple hardness grades

Typical Applications: Grips, handles, wearable products, protective covers and automotive interiors.

Available Finishes: Bonding is grade- and substrate-specific. Not every TPE or TPU will chemically bond to every rigid thermoplastic.

Surface Finishing & Secondary Operations

Surface requirements should be considered together with tooling design, resin selection, and final application.

Finishing Option	Result & Engineering Considerations	Suitable Materials / Processes	Typical Applications
Mold Texture / SPI Finish	Controls gloss and texture directly in the mold. Textured surfaces generally require additional draft and make parting-line and shutoff planning more important	Most thermoplastics and suitable LSR tools	Visible housings, grips, automotive interiors and consumer products
As Molded	Lowest secondary-processing cost. Gate, parting-line and ejector witness remain unless tooling and process design minimize them	Most injection-molding materials	Internal components, functional prototypes and production parts
Vapor / Solvent Polishing	Can improve surface smoothness and optical clarity on compatible resins; residual stress and chemical compatibility must be evaluated	Selected PC, PMMA and transparent plastics	Clear covers, optical housings and display components
Painting	Adds specified color, texture or coating performance. Mask mating and sealing surfaces and account for coating thickness	ABS, PC, PC+ABS and properly treated PP/PE or engineering plastics	Consumer housings, automotive parts and medical-device housings
Pad Printing / Silk Screening	Adds logos, symbols and product information. Surface curvature, texture and ink adhesion affect print sharpness	Most suitable molded plastics	Controls, housings, buttons and branded parts
Laser Marking	Provides durable identification without ink. Contrast depends on resin, pigment, fillers and laser settings	Engineering plastics and laser-markable grades	Serial numbers, traceability codes and permanent markings
Plating	Adds a metallic decorative or functional layer. Substrate preparation and coating thickness matter at snaps and mating interfaces	ABS and selected platable plastics	Automotive trim and decorative electronics components
Assembly & Secondary Operations	Includes inserts, bonding, ultrasonic welding, tapping, machining and component integration. Joint design and tolerance stack should be defined before release	Thermoplastics, elastomers and mixed assemblies	Finished subassemblies and ready-to-install parts

Injection Molding Equipment & Inspection Capabilities

Production Equipment (Demo)

Process Control Equipment (Demo)

Inspection Equipment (Demo)

Injection Molding Project Showcase

Why Choose Mastars for Injection Molding?

Certified Quality Systems

ISO 9001, ISO 13485, and IATF 16949 certified processes help ensure consistent quality across industrial, medical, and automotive projects.

100+ Engineering Professionals

Work directly with experienced engineers for DFM reviews, tolerance recommendations, and manufacturing support—without unnecessary back-and-forth.

5+ Production Bases

Flexible manufacturing capacity supports both urgent prototypes and scalable production without single-site bottlenecks.

No Minimum Order Quantity

Order one part or thousands—without unnecessary volume commitments or tooling investments.

DFM Review on Every Order

Identify manufacturability risks early to reduce redesign cycles, save costs, and improve part performance before production begins.

800+ Customers Served

Trusted by global engineering teams across industrial equipment, medical devices, robotics, automotive, and consumer products.

Certifications

ISO9001:2015 Certificate

IATF16949:2016 Certificate

ISO13485:2016 Certificate

Medical A-Class Supplier

Partners

How Injection Molding Works

Upload Your Design

Share your CAD files, drawings, quantity, material, and any critical requirements.

Get an Engineer-Reviewed Quote

Receive pricing, lead time, and manufacturability feedback based on your part requirements.

Production Begins

Once you approve your quote, manufacturing starts — from prototype tooling to full-scale runs.

Parts Shipped

Finished parts are inspected, packaged, and shipped with the required quality documentation.

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